"You do not think he referred to the mark on his own hand?"
"I think not. From the direction of his last glance, I feel sure he referred to something in the study."
"What did you do?"
"Having summoned the servants, I ran into the study. But there was absolutely nothing unusual to be seen. The windows were closed and fastened. He worked with closed windows in the hottest weather. There is no other door, for the study occupies the end of a narrow wing, so that no one could possibly have gained access to it, whilst I was in the library, unseen by me. Had someone concealed himself in the study earlier in the evening—and I am convinced that it offers no hiding-place—he could only have come out again by passing through here."
Nayland Smith tugged at the lobe of his left ear, as was his habit when meditating.
"You had been at work here in this way for some time?"
"Yes. Sir Crichton was preparing an important book."
"Had anything unusual occurred prior to this evening?"
"Yes," said Mr. Burboyne, with evident perplexity; "though I attached no importance to it
